Process for the production of aluminum alkyls



United States Patent US. Cl. 260-448 6 Claims ABSTRACT OF THE DISCLOSURE Process for the manufacture of primary alcohols by isomerizing an aluminum secondary alkyl to an aluminum primary alkyl wherein the aluminum secondary alkyl is heated at 50 to 250 C. for about /210 hours with about 0.5-10 mole percent of Group IV-B catalyst, based on aluminum secondary alkyl, and oxidizing the resulting aluminum primary alkyl product to form an aluminum alkylate followed by hydrolysis of the alkylate to the corresponding alcohol.

This application is a continuation-in-part of copending application of E. W. Miiller et al., US. Ser. No. 323,052, filed Nov. 12, 1963 and now abandoned.

This invention relates to the preparation of primary alcohols from internal olefins. More specifically, it relates to the preparation of aluminum primary alkyls by a catalytically accelerated structural isomerization of aluminum secondary alkyls and the subsequent conversion of the resulting aluminum primary alkyls to the corresponding alcohols.

Normal primary alcohols are particularly useful products, the higher primary alcohols being especially suitable as detergent intermediates. They may be obtained through a series of reactions, the first of which involves the conversion of aluminum secondary alkyls by an isomerization treatment into aluminum primary alkyls. Thermal isomerization as described in French Patent 1,285,405 can be employed, or a dispersion of finely divided sodium in an inert hydrocarbon can be used to catalyze the isomerization as described in US. 3,116,310. Subsequent oxidation of the resulting aluminum trialkyl with, for instance, air, produces thealkoxide which in turn can be hydrolyzed with, e.g., water or dilute acid to obtain the primary alcohol. This process for the production of primary alcohols has been limited by the fact that the thermal isomerization of the aluminum secondary alkyls requires a long reaction time and high temperature, while sodium dispersions are undesirably expensive, and inconvenient to use as catalysts.

It is, therefore, a principal object of the present invention to provide an efficient and economical method for converting aluminum secondary alkyls to aluminum primary alkyls by catalytic isomerization and to produce primary alcohols from the aluminum primary alkyls produced thereby.

These and other objects will be better understood from the description of the invention as given hereinafter.

Now, in accordance with this invention, it has been found that the rate of isomerization of aluminum secondary alkyls to aluminum primary alkyls is greatly enhanced when the conversion is performed in the presence of certain materials which catalyze the reaction. It has now been found that certain transition metals catalyze the reaction to such a degree that the conversion of alumi- 3,475,477 Patented Oct. 28, 1969 num secondary alkyls to aluminum primary alkyls becomes commercially feasible. The process comprises therefore reacting an aluminum secondary alkyl in the presence, as catalyst of a transition metal of Group IV-B of the Periodic Table of the Elements as published, for example in Langes Handbook of Chemistry, Tenth Edition (1961) McGraw-Hill Book Company, pages 58 and 59, i.e., the metals of atomic numbers 22, 40 and 72, namely titanium, zirconium and hafnium.

Catalysts with which surprisingly good results have been obtained are derived from compounds containing titanium and/or zirconium, with titanium being most preferred. The catalyst may be added to the aluminum secondary alkyl reactant in various forms. One convenient method is to add to the aluminum alkyl a compound of the catalyst metal.

There are advantages if the Group IV-B metal catalyst is added in the form of a compound containing an oxygen atom linking the metal with a carbon atom, such as alcoholate, phenolate or a chelate. Suitable compounds of this type are the methylates, ethylates, propylates, isopropylates, phenolates, cresolates, acetylacetonates, salicylates, benzoylacetonates, and 2-furoylacetonates, with alcoholates and chelates of fl-diketones such as the acetylacetonates being particularly suitable, although salts of the chosen Group IV-B metal, for example, halides, especially chlorides of titanium, zirconium and hafnium are another useful form in which to add the catalyst in the new process.

By aluminum secondary alkyl is meant:

wherein R is a secondary alkyl of 4 to 30 carbon atoms and each R represents a primary or secondary alkyl or hydrogen. Advantageously the alkyl groups represented by R' are primary alkyl groups of 1 to 20 carbon atoms or secondary alkyl groups of 3 to 20 carbon atoms. The invention offers special advantage with starting aluminum alkyls having at least one secondary alkyl of 8 to 20 carbon atoms.

Examples of the aluminum secondary alkyl starting materials are, for instance, di-sec.-dodecylaluminum hydride, di-isobutyl-sec.-octylaluminum, di-sec.-decyl-isopropylaluminum, di-sec.-tride'cylaluminum hydride, disec. nonylaluminum hydride, tri pentadecylaluminum, and the like.

The aluminum secondary alkyl starting materials may be obtained by methods well known to the art, i.e., by reacting a non-alpha-olefin or a mixture of such olefins, e.g., a mixture of octenes having double bonds in various, mainly non-terminal positions, with a relatively low molecular weight aluminum alkyl such as, e.g., di-isobutylaluminum hydride. This reaction would result in the production of an aluminum secondary alkyl compound. Suitable non-alpha-olefins include: butene-2, pentene-2, hexene-Z, or -3, octene-2, -3 or -4, decene-S and tridecene- 6. These may be obtained by, e.g., the dehydration of suitable alcohols or alcohol mixtures. Advantage'ously, a mixture of technical non-a-olefins is used, which preferably contains olefins of at least 8 carbon atoms per molecule. Such technical mixtures can be obtained, for example, from olefin fractions high in alpha-olefins such as are produced by thermal or catalytic cracking of petroleum hydrocarbon. These are usually fractionated into distillation cuts containing, for instance, C -C Cry-C 3, (D g-C16, and C14-C13 olefins. The alpha-olefins in such mixtures being much more reactive than the non-alpha-olefins, can be reacted preferentially, e.g., by polymerization, and the non-alpha-olefin content in the unreacted olefinic residue thus increased extensively. A product can be fractionated from this residue which is nected to the vessel. Excess octenes (21.3 grams) were then taken overhead, leaving a liquid colorless product which was di-isobutyl-octyl-aluminum.

The nature of the octyl groups present was determined by bubbling 11.9 grams of the product for 5 hours at predominantly internal olefin and particularly useful in a room temperature with subsequent treatment for another making aluminum secondary alkyls suitable as starting 20 hours in pure oxygen. The oxidation product was added materials for the process of the invention. to 25 milliliters of hydrochloric acid and thereafter By non-alpha-olefin is meant an olefinic hydrocarbon extracted with ether. The extract was dried over sodium or a mixture of such hydrocarbons having the olefinic 10 sulfate. The ether was taken overhead leaving a product double bond in a position other than a terminal one in containing in addition to isobutanol and a small amount a substanltiall1 prolportiorgtgf tiehmoleclulesl, in plltlcllill Ff etflieri12.77 grams 11(7772;1 of thectlary) of otfztanoils. By one in w ie at east 4 0 o t e mo ecu es an pre eriqui c romatograp yt is pro uct was oun to conably at least 60%, have the olefinic double bond in a tain 22.3% octanol-l the remaining 77.7% being octanolnon-terminal position. 15 2, -3, and -4.

In carrying out the process, the chosen compound of Two 11.9 gram samples of the di-isobutyl-secondary the Group IV-B, metal is added to the reaction mixture octyl aluminum were isomerized by heating at 110 C. in catalytic amounts, i.e., in an amount which may vary for 8 hours after addition of 0.25 grams of zirconium from, e.g., about 0.05 to about 10 mole percent, in partetrachloride, and ml. of titanium tetraisopropylate, ticular from 0.5-5 mole percent, based on the amount of 20 respectively. The resulting products were oxidized, hydroaluminum secondary alkyl compound employed. Smaller lyzed, and worked up in the same way as the foregoing or larger amounts may be used, of course, if desired. control with the following results:

Product Com- Yield of Octanols position, percent Percent Octa- Example Catalyst Amount Grams of Theory nol-l Others Control 2.77 77 22.3 77.7 I ZrCli 0.25 grams 2.4 67 53.8 46.2 II Ti-tetraisopropylate... 0.25 ml 2.25 63 100 0 Suitable reaction conditions for preparation of alumi- Similar isomerization is achieved by substituting zirconnum primary alkyls according to the invention include ium tetraethylate and titanium tetrachloride as catalysts temperatures from about 50 C. to about 250 0, pre- 0 under the foregoing conditions.

0 g o ferably between S0 C. and 200 C., the reaction being EXAMPLE HI conveniently carried out in an inert atmosphere such as U h th d f th f 1 d nitrogen or argon. It has been found that at higher temg t 6 me 0 5 P e orgolflg P f peratures smaller amounts of catalyst and shorter reaction 40 ondary dodecyl 1111111111111? yf 1S lsomerlled Wlth times are required. 'lghus, it hlassobegn fogntzlsglatcat 2 53 fg p e fi g g i y g action temperatures etween an t e 0X1 123100, Y an P In 6 m optimum amount of catalyst can be decreased to 0.1 2% Way a good Yield of nprmal dodecyl alcohol is Obtainei mole. A reaction time 5-10 hours Will generally be sufii- Substitution of titanium triethylate chloride or hafnium cient at temperatures between 100 C. and 150 C., while tetraisopropylate as isomfirilafiqll Catalysts Produce Simi' between 150 c. and 200 0. reaction times of /2-5 lar results under analogous conditwnshoturls may tbe usteddfizt tctlemperatures above 180 C. some EXAMPLE Iv caays sys ems en 0 ecompose. I

in pressure ave no a verse e ect on t e reaction; su

:1 t tit 22:57.57.2 32273217573217; e auminum primary a ys pro uce accor mg to the invention can be converted into a variety of deriva- Pexadefiyl after oxl lon and hydrolys1s of the tives by reaction with, e.g., S0 producing sulfinic acids, lsomenzaflon P F n or with CO resulting in the formation of carboxylic acids. 55 We clalm as our "P AS the are pre era y 0x1 ize e.g., wit oxygen or air, to convert primary alkyl formed in the isomerization to an contams from carboon 310K150 Pyc f g 3 alcoholate group and form the corresponding aluminum Hum Secondary a y at 50 25 -0 a g 2 i s alkylates. Subsequently the alkylates may be hydrolyzed about 10 hours Wlth as Cam Y about to 3 out to form the correspondin primary alcohols according to mole Percent of Group metal Compounds Selected methods well known in art from the group consisting of alcoholates, phenolates, beta- The following specific examples of th i v ti ill ketone chelates, and chlorides, sa1d mole percent based serve to illustrate more clearly the application of the inon said alummuffl Secondary lf 1 vention but it is not to be construed as m any manner A P F 1n accordamfe C 1 Wherem limiting the invention. mum catalyst is used for the isomenzation.

3. A process in accordance with claim 2 wherein the EXAMPLES I AND H isomerization catalyst is added as alcoholate.

50 grams of diisobutyl aluminum hydride and 39.5 4. A process in accordance with claim 3 wherein grams of a mixture of isomeric n-octanes (containing titanium tetra-isopropylate is added in the isomerization. about 2% of octane-1, the remainder being n-octenes hav- 5. A process in accordance with claim 1 wherein ziring double bond in an internal position) were placed in a suitable vessel at C. for 70 hours. Negligible amounts of isobutene were collected in a cold trap conconium catalyst is used for the isomerization.

6. A process in accordance with claim 1 wherein the isomerization is performed in an inert atmosphere with 5 *6 0.5 to 5 mole percent of said catalyst using a reaction FOREIGN PATENTS time of 5 to 10 hours and a temperature between about 1,006,843 10/1965 Great Britain and about150 0 1,285,405 1/1962 France.

1,365,413 5/1964 France. References Cited 5 UNITED STATES PATENTS TOBIAS E. LEVOW, Primary Examiner 3 116 310 12/1963 Bade et a1 H. M. S. SNEED, Assistant Examiner 3,282,974 11/ 1966 Bruno et al. US, Cl, X.R.

3,322,806 5/1967 Asinger et a1. 10 260-632 

